Tyson Gay’s positive test was for a banned steroid

American sprinter Tyson Gay tested positive for a banned steroid that could lead to a two-year suspension, it was revealed today.

The 2007 100 metres world champion failed a test last month but details of the substance he tested positive for had not been made public.

But the BBC have obtained extracts of a letter sent to Gay by the United States Anti-Doping Agency which outlines the nature of the substance traced in a sample he gave to drug testers during the US World Championship trials in June. The letter, dated July 23, states: “Using the Carbon Isotope Ratio Analysis it reported that the sample had an adverse analytical finding reflecting values that are consistent with the administration of a steroid of exogenous [external] nature.”

The letter also says that a positive test for an “anabolic agent” of this kind would — if proven — be a violation of the World Anti-Doping Agency code.

The standard ban for an athlete found guilty of taking a prohibited steroid is two years.

Usada, who confirmed on July 27 that the 31-year-old failed at least two tests, refused to comment on whether Gay had tested positive for a steroid. It is understood that in addition to the positive sample he gave at the US trials, he failed an out-of-competition test in May.

After learning of his first failed test, Gay pulled out of the American team for the World Athletics Championships held in Moscow earlier this month.

“I don’t have a sabotage story,” said Gay last month. “I basically put my trust in someone and was let down. I know exactly what went on but I can’t discuss it right now.”